F67Documented failure WCAG 1.1.1 WCAG 1.2.1 Level A Human testing required

Do not write long descriptions that miss the point

The long description is there, and it is not carrying what the picture carries. F67 is the failure technique for that gap, so a page matching it holds a defect rather than a fix. The trap is that these descriptions are usually useful. A street map described by which sports run at which venue tells you something real and still leaves out the addresses and the distances, which were the whole reason for a map. A chart described as colorful does the same thing. So does a video write-up that drops the numbers. Useful enough to sound finished is the shape this one takes, and on an interactive diagram it costs more than facts, because a reader who never hears about the parts you can click cannot work the thing at all.

How we find it in an audit

No scanner can weigh a description against the thing it describes, so a person reads every one. Our reviewers study the chart, diagram or clip first, write down what a sighted viewer walks away with, then read the description and list what never crossed over. A long description does not have to be prose either. For a chart, a table of the actual numbers usually carries more than a paragraph can, and it counts as the description.

How affected users experience it

A blind reader who follows a long-description link trusts it to be the whole story, because that is the promise the link makes. When it is not, they finish confident and short of the facts, with nothing in the page to flag the gap. That confidence is the damage. A missing description at least announces itself, while a description that answers the wrong question sends someone away believing they have what everyone else has.

Passes vs. fails

Passes: alt text names the product. Fails: the file name is all there is.

Passes

<img src="q3-sales.png" alt="Q3 sales by region, with the figures in the table below">
<table><caption>Q3 sales by region</caption>
<tr><th>North</th><td>$410k</td></tr><tr><th>South</th><td>$380k</td></tr>
<tr><th>East</th><td>$290k</td></tr><tr><th>West</th><td>$255k</td></tr></table>

Fails

<img src="q3-sales.png" alt="Q3 sales chart" aria-describedby="desc">
<p id="desc">A colorful bar chart showing quarterly sales.</p>

How this gets tested

The W3C publishes test rules that define what a checker looks for here.

Element marked as decorative is not exposedA tool can check this
Image accessible name is descriptiveA tool finds candidates, you decide
Image button has non-empty accessible nameA tool can check this
Image has non-empty accessible nameA tool can check this
Link has non-empty accessible nameA tool can check this
Object element rendering non-text content has non-empty accessible nameA tool can check this
SVG element with explicit role has non-empty accessible nameA tool can check this
Image not in the accessibility tree is decorativeA tool can check this
Audio element content has text alternativeA tool finds candidates, you decide
Video element visual-only content has accessible alternativeA tool finds candidates, you decide

The other techniques filed under this rule

39 guides on this site are filed under 1.1.1 Non-text Content. W3C documents this one as a failure of that rule, so it describes a way the rule gets broken rather than a way to pass it.

This guide is our interpretation of W3C technique F67: Failure of Success Criterion 1.1.1 and 1.2.1 due to providing long descriptions for non-text content that does not serve the same purpose or does not present the same information. W3C publishes its techniques as guidance rather than as the standard, and says so on every one of them. The success criterion is what conformance is measured against, and a technique is one documented way to meet it.